1. Field of the Invention
The invention relates to a pressure differential measuring apparatus wherein a resilient bendable tubular member acting as a measuring spring surrounds a control rod which is firmly connected to one end of the tubular member.
2. Description of the Prior Art
In one known pressure differential measuring apparatus of the above type, the resilient tubular member serves at the same time as a feedthrough for coupling the measured differential pressure from the measuring chamber of the measuring apparatus. This simplifies the design of the measuring apparatus and facilitates production. However, the aforesaid type of measuring apparatus is not able to be constructed with a minimum degree of compactness. This is due to the fact that such a construction of the apparatus requires that the gap between the control rod and the interior surfaces of the tubular member be maintained at a few tenths of a millimeter over the relatively great length of the rod.
It is therefore an object of the present invention to provide an improved pressure differential measuring apparatus of the above type.